This allows one to choose the fastest approximation suitable for a given application. ISBN978-1-4020-6948-2. ^ Winitzki, Sergei (6 February 2008). "A handy approximation for the error function and its inverse" (PDF). Retrieved 2011-10-03. ^ Chiani, M., Dardari, D., Simon, M.K. (2003). Return ValuesArithmetical expressionAlgorithmserf, erfc, and erfi are entire functions. The function also accepts symbolic values of n.If n is a numerical value, you can use expand(erfc(x, n)) to apply th...